Performance Maintaining Method For Electrolyzed Functional Water Generating Apparatus

ABSTRACT

A performance maintaining method for an electrolyzed functional water generating apparatus capable of maintaining a state allowing steady generation of high-performance electrolyzed functional water is provided. A cation-exchange membrane provided in contact with an anode between a cathode and the anode regenerates a membrane by desorbing cations adsorbed to the cation-exchange membrane while to-be-electrolyzed raw water is subjected to electrolysis with a positive polarity in a state where an electrolytic chamber is supplied with to-be-electrolyzed raw water in the electrolyzed functional water generating apparatus having an electrolytic cell with a special structure that allows intake of the entire amount of water as cathode water.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electrolyzed functional watergenerating apparatus configured to provide functionality to water byelectrolyzing to-be-electrolyzed raw water. More specifically, itrelates to a performance maintaining method for the electrolyzedfunctional water generating apparatus capable of maintaining a stateallowing steady generation of high-performance electrolyzed functionalwater.

2. Related Background Art

Electrolyzed functional water is water that has acquired a usefulfunction with reproducibility through an electrochemical reactionoccurring by causing an electrical current to flow to an electrolyticaqueous solution. The electrolyzed functional water generating apparatusis an apparatus designed for the purpose of generating the electrolyzedfunctional water.

An exemplary prior art electrolyzed functional water generatingapparatus is disclosed in Patent Document 1 proposed by the applicantsof the present invention, comprising: an electrolytic chamber to whichto-be-electrolyzed raw water is supplied; at least one separatingmembrane which separates the inside of the electrolytic chamber from theoutside thereof; a pair of electrode plates provided inside and outsidethe electrolytic chamber sandwiching the separating membranetherebetween; an electrolytic cell in which the electrode plate outsidethe electrolytic chamber is provided in contact with the separatingmembrane or leaving a slight space; and a power source that supplies anelectrolyzing voltage to the electrolytic cell. Moreover, technique forconducting electrolysis of the to-be-electrolyzed raw water by applyinga voltage from the power source between the electrode plate provided asthe cathode inside the electrolytic chamber and electrode plate providedas the anode outside the electrolytic chamber using an electrolyte filmsuch as a cation-exchange membrane or an anion-exchange membrane as theseparating membrane is disclosed.

Furthermore, Patent Document 2 discloses an electrolyzedhydrogen-dissolved water generating apparatus constituted by: anelectrolytic cell, which includes a cathode and an anode deployed facingeach other, an electrolytic film arranged in contact with the anodebetween the cathode and the anode, and a cathode chamber in which thecathode is deployed; a raw water path, which directly connects to thecathode chamber to continuously pass raw water thereto; and anelectrolyzed water discharge channel, which directly connects to thecathode chamber to drain from the electrolytic cell electrolyzedhydrogen-dissolved water, which dissolves hydrogen generated on thecathode surface.

However, the electrolyzed functional water generating apparatusdescribed in Patent Documents 1 and 2, which has the separating membraneprovided in contact with the anode between the cathode and the anode andthe electrolytic cell with a special structure that allows intake of theentire amount of water as cathode water, has a deep-seated problem thatthe serviceability of the apparatus is inhibited due to separatingmembrane characteristics in the case of employing an electrolytic film,particularly a cation-exchange membrane as the separating membrane andalso employing water containing hardness components (e.g., calcium ionsor magnesium ions) such as tap water or mineral water.

More specifically, by exposing the cation-exchange membrane to the watercontaining hardness components, it can have a property of selectivelyadsorbing cations in the water as with cation-exchange resin. When thecation-exchange membrane having said property is employed as theseparating membrane of the special structured electrolytic cell asdescribed in Patent Documents 1 and 2, the cation-exchange membrane isalways in contact with the to-be-electrolyzed raw water existing in theelectrolytic cell, thereby adsorbing the cations from the hardnesscomponents within the to-be-electrolyzed raw water. This brings about adeep-seated problem that steady generation of high-performanceelectrolyzed functional water may be no longer possible. The presentinvention employs the concentration of hydrogen dissolved into theelectrolyzed functional water as an indicator for measuring propertiesthereof. According to this indicator, high-performance electrolyzedfunctional water is water in which highly concentrated electrolyzedhydrogen is dissolved such as electrolyzed hydrogen-saturated water(including electrolyzed hydrogen supersaturated water) in which hydrogengenerated through electrolysis of water is dissolved to a degreeexceeding the saturated concentration.

[Patent Document 1] Patent Gazette No. 3349710 [Patent Document 2]Japanese Patent Application Laid-open No. 2003-245669 SUMMARY OF THEINVENTION

The present invention has been made for solving the above problem andhas an object to provide a performance maintaining method for anelectrolyzed functional water generating apparatus capable ofmaintaining a state allowing steady generation of high-performanceelectrolyzed functional water.

In order to solve the above-given problem, a performance maintainingmethod for an electrolyzed functional water generating apparatusaccording to the invention set forth in claim 1, which comprises anelectrolytic chamber to which to-be-electrolyzed raw water is supplied,at least one separating membrane which separates the inside of theelectrolytic chamber from the outside thereof at least a pair ofelectrode plates provided inside and outside the electrolytic chambersandwiching the separating membrane, an electrolytic cell in which theelectrode plate outside the electrolytic chamber is provided in contactwith the separating membrane, and a DC power source that supplies a DCvoltage between electrodes in the electrolytic cell; said method ischaracterized by employing a cation-exchange membrane as the separatingmembrane and comprising: regenerating a membrane by applying a DCvoltage from the DC power source between a cathode or an electrode plateprovided inside the electrolytic chamber and an anode or an electrodeplate outside the electrolytic chamber in a forward direction in a statewhere the electrolytic chamber is supplied with to-be-electrolyzed rawwater; wherein cations such as calcium ions or magnesium ions adsorbedinto the cation-exchange membrane are desorbed while theto-be-electrolyzed raw water is subjected to electrolysis in the forwarddirection so as to regenerate the membrane.

The invention set forth in claim 1 is made to resolve a new problem thatsteady generation of high-performance electrolyzed functional water maybe impossible when trying to generate the electrolyzed functional waterunder the condition of cations adsorbed into the cation-exchangemembrane in the electrolytic cell according to the present invention, bydesorbing the cations adsorbed into the cation-exchange membrane in astate where the electrolytic chamber is supplied with to-be-electrolyzedraw water while subjecting the to-be-electrolyzed raw water toelectrolysis with a positive polarity so as to regenerate the membrane.

The principle of such membrane regeneration through electrolysis isdescribed forthwith. When to-be-electrolyzed raw water is subjected toelectrolysis with a positive polarity, an electrochemical reactionrepresented by the reaction formula:

4H₂O+4e ⁻→2H₂↑4OH⁻

occurs on the surface of the anode provided in the electrolytic chamber,generating hydroxide and hydrogen ions. Meanwhile, an electrochemicalreaction represented by the reaction formula:

2H₂O→O₂↑4H⁺+4e ⁻

occurs on the surface of the anode provided in contact with thecation-exchange membrane, or more specifically, between the anode andthe cation-exchange membrane, generating hydroxide and hydrogen ions.

Due to the abundant hydrogen ions generated on the anode surface in thismanner, cations such as calcium ions or magnesium ions adsorbed into thecation-exchange membrane are substituted with the hydrogen ions and thusbroken away from the cation-exchange membrane, resulting in accelerationof regeneration of the membrane.

According to the invention set forth in claim 1, subjectingto-be-electrolyzed raw water to electrolysis with a positive polarity ina state where the to-be-electrolyzed raw water is supplied to theelectrolytic chamber allows desorption of the cations to regenerate thecation-exchange membrane, resulting in elimination of the contributingfactor preventing to steadily generate high-performance electrolyzedfunctional water. Therefore, the electrolyzed functional watergenerating apparatus can maintain a state allowing steady generation ofhigh-performance electrolyzed functional water.

With the invention set forth in claim 1, an idea including generalmembrane regenerating technology through electrolysis, which desorbscations adsorbed into the cation-exchange membrane while subjecting theto-be-electrolyzed raw water to electrolysis with a positive polarity ina state where the electrolytic chamber is supplied withto-be-electrolyzed raw water so as to regenerate the membrane, isprovided. However, can the cation-exchange membrane be regenerated aslong as the to-be-electrolyzed raw water is subjected to electrolysis?As a result of the inventers devoted research regarding this question,it is found that simply applying a DC voltage from the DC power sourcein a forward direction is insufficient to desorb the cations adsorbedinto the cation-exchange membrane and that there is a necessity tosatisfy a certain requirement in order to accomplish the end desire,thereby completing the invention set forth in claim 2.

In other words, the invention set forth in claim 2 is characterized bysetting a current density of the anode to a value exceeding a criticalcurrent density or the lower limit in order to desorb cations adsorbedinto the cation-exchange membrane when a DC voltage from the directcurrent source is applied in the forward direction between bothelectrodes.

According to the invention set forth in claim 2, since the currentdensity of the anode is set to a value exceeding a critical currentdensity or the lower limit that allows desorbing of the cations adsorbedinto the cation-exchange membrane as an electrolysis requirementnecessary for cation-exchange membrane regeneration throughelectrolysis, cation-exchange membrane regeneration through electrolysiscan be assuredly conducted. Note that critical current density has closerelationships with the state of the membrane itself including anabsolute amount of cation adsorption to the cation-exchange membrane andtype and ratio of the adsorbed cations, and the environmental conditionof the surrounding in which the cation-exchange membrane is deployedincluding hardness of the to-be-electrolyzed raw water in which thecation-exchange membrane is immersed, type and ratio of both anions andcations dissolved in that water, and the pH of that water. In otherwords, when, for example, the absolute amount of cation adsorption tothe membrane and rise and fall of the hardness of the to-be-electrolyzedraw water in which the cation-exchange membrane is immersed change,critical current density changes responding thereto. More specifically,as shown in FIGS. 13 through 16, for example, it is also experimentallydemonstrated that critical current density tends to be a low value inthe case where the to-be-electrolyzed raw water in which thecation-exchange membrane is immersed is soft water, while it tends to bea high value in the case where the membrane-immersing water is hardwater.

With the invention set forth in claim 2, an electrolysis requirementnecessary for surely implementing cation-exchange membrane regenerationthrough electrolysis is specified. Now that a guideline forcation-exchange membrane regeneration through electrolysis isestablished, it is imperative from a practical standpoint to grasp atsome point to what extent are cations adsorbed into the cation-exchangemembrane because it will be useful for providing a performance guaranteefor the resulting electrolyzed functional water in view of the fact thatthere is correlation between the adsorption rate of cations to themembrane and performance of the electrolyzed functional water.

In light of this, the invention set forth in claim 3 is characterized bygrasping a regeneration level of the cation-exchange membrane based onchanges in PH over time of electrolyzed functional water resulting fromsubjecting the to-be-electrolyzed raw water to the electrolysis with apositive polarity.

With the invention set forth in claim 3, when observation of changes inPH of electrolyzed functional water resulting from subjecting theto-be-electrolyzed raw water to the electrolysis with a positivepolarity has found no changes in PH over time (the pH is nearly constantand does not fluctuate), which means that the regenerating level of thecation-exchange membrane approaches a state of equilibrium (idealstate), the regenerating level of the cation-exchange membrane is thengrasped based on changes in PH of electrolyzed functional waterresulting from subjecting the to-be-electrolyzed raw water to theelectrolysis with a positive polarity over time. Here, the regeneratinglevel of the cation-exchange membrane denotes a relative regeneratinglevel with an ideal regenerating level of the cation-exchange membraneas a standard at the point where the aforementioned mutual relationshipbetween the state of the cation-exchange membrane itself and thesurrounding environmental condition in which the cation-exchangemembrane is deployed reaches a state of equilibrium. Furthermore, anideal regenerating level of the cation-exchange membrane at the pointwhere the above-given mutual relationship reaches a state of equilibriumdenotes a state allowing a predetermined amount of cations to be storedin the cation-exchange membrane without more than the predeterminedamount of cations continuing to be adsorbed and also allowing hydrogenions generating in the anode to permeate and continue being supplied tothe electrolytic chamber.

According to the invention set forth in claim 3, the regenerating levelof the cation-exchange membrane is grasped based on changes in PH ofelectrolyzed functional water resulting from subjecting theto-be-electrolyzed raw water to the electrolysis with a positivepolarity over time. Therefore, provision of, for example, a pH sensor inthe electrolyzed functional water generating apparatus and thendetection of changes in PH over time while the to-be-electrolyzed rawwater is subjected to the electrolysis with a positive polarity allowfinding of the regenerating level of the cation-exchange membrane aswell as the performance of the resulting electrolyzed functional water.Note that the present invention may be configured to terminatecontinuance of the membrane regenerating process assuming thatregeneration of the membrane is complete when the grasped regeneratinglevel of the cation-exchange membrane has reached a predetermined level.This allows optimization of the duration of the membrane regeneratingprocess.

With the invention set forth in claim 3, necessary technicalspecifications for grasping the relative regenerating level of thecation-exchange membrane is provided. After a method for grasping therelative regenerating level of the cation-exchange membrane isestablished, clarifying how to resolve the scale adhesion problem of thecathode inevitably occurring during water electrolysis (i.e., problemthat calcium hydroxide or magnesium hydroxide solidifying andaccumulating on the surface of the cathode causes deterioration of theelectrolysis efficiency and the like; see FIG. 11) and the disinfectionand rinsing problem of the water flow path in the apparatus becomes anextremely important factor for increasing the practical value of thepresent invention. Furthermore, as described later, the cation-exchangemembrane employed with the present invention has properties thatsufficiently demonstrate the functionality thereof in an aqueous state.However, it loses that functionality when exposed in a dry state,causing extreme deterioration of the electrolysis efficiency. When insuch a situation, demonstrating how to recover functions of theapparatus becomes an extremely important factor for increasing thepractical value of the present invention.

In view of this, the invention set forth in claim 4 is characterized byfurther comprising a reverse descaling process of applying a DC voltagewith a reverse polarity from the DC power source between the cathode orthe electrode plate provided inside the electrolytic chamber and theanode or the electrode plate outside the electrolytic chamber in a statewhere to-be-electrolyzed raw water is supplied to the electrolyticchamber.

According to the invention set forth in claim 4, since a reversedescaling process is provided, the scale adhesion problem of the cathodeand the disinfection and rinsing problem of the water flow path in theapparatus can be resolved at once. Furthermore, when in the situationwhere the cation-exchange membrane is exposed in a dry state, speedyrecovery of the functions of the apparatus may be implemented bycarrying out the reverse descaling process, thereby leading to excellentpractical advantages.

According to the invention set forth in claim 4, providing a reversedescaling process is specified in order to resolve all at once the scaleadhesion problem of the cathode and the disinfection and rinsing problemof the water flow path in the apparatus and the problem of losingfunctionality of the apparatus due to drying of the cation-exchangemembrane. However, when the reverse descaling process is carried out,the polarity of the electrode plate provided outside the electrolyticchamber becomes negative, the cations existing within theto-be-electrolyzed raw water in the electrolytic chamber are influencedto be attracted to the cation-exchange membrane, and as a result of thecation-exchange membrane adsorbing a large amount of cations (see FIG.12), membrane regeneration becomes imperative.

In view of this, the invention set forth in claim 4 is characterized bythe membrane regenerating process carried out after the reversedescaling process.

According to the invention set forth in claim 5, even if a large amountof cations adsorb into the cation-exchange membrane due to carrying outthe reverse descaling process, the membrane regenerating process iscarried out after the reverse descaling process, and thus the end desiremay be achieved by eliminating adverse affects from carrying out thereverse descaling process.

Incidentally, even if the cations adsorbed to the cation-exchangemembrane are nearly all desorbed due to carrying out the membraneregenerating process, when the apparatus is left as is in anelectrolysis off state, adsorption to the membrane of the cations suchas calcium ions or magnesium ions existing within the residual water inthe electrolytic chamber gradually progresses at the same time assubstitution and discharge of the hydrogen ions after the point when themembrane reproducing process is completed as a borderline, as shown inthe simplified explanatory diagram focusing on behaviors of thematerials in the electrolytic chamber of FIG. 7. This may emanate fromthe fact that in the case where a cation-exchange membrane such as aperfluorinated sulfonic acid membrane is immersed in an aqueous solutioncontaining a plurality of cation components differing in type, thecation components are preferentially desorbed to the membrane in theorder of calcium ions, magnesium ions, potassium ions, sodium ions, andhydrogen ions. At this time, focusing on the characteristics of theresidual water in the electrolytic chamber, the hardness thereofdecreases and the pH thereof becomes more acidic. The adsorptionprogression rate of the cations into the membrane gradually slows downas the mutual relationship based on parameters such as hardness of theresidual water in the electrolytic chamber, adsorption rate of cationsinto the membrane, and pH of the residual water approaches a state ofequilibrium; and at the point when the state of equilibrium is reached,the progression of adsorption may stop. Given this, when initiatinggeneration of electrolyzed functional water, adsorption of cations intothe membrane has progressed until the membrane regenerating process isrequired. In this case, if obtaining high-performance electrolyzedfunctional water is first priority, the generating process for theelectrolyzed functional water is inevitably carried out after themembrane regenerating process is carried out. This prevents immediateprovision of high-performance electrolyzed functional water. Such asituation will occur quite frequently with the electrolyzed functionalwater generating apparatus designed to be distributed in homes, forexample.

In view of this, the invention set forth in claim 6 is characterized bythe membrane regenerating process intermittently carried out.

According to the invention set forth in claim 6, since the membranegenerating process is carried out intermittently, for example, and anautomatic membrane regenerating process is carried out for five minutesevery twelve hours or for twenty-five minutes every thirty minutes evenin a case where the apparatus is not used for a relatively long periodsuch as three days, regularly maintaining performance of theelectrolyzed functional water generating apparatus at a high level ispossible. Therefore, In the case of applying the performance maintainingmethod according to the present invention to the electrolyzed functionalwater generating apparatus for domestic use, high-performanceelectrolyzed functional water can be provided immediately as needed.This allows provision of an apparatus with high customer satisfaction.

Furthermore, the invention set forth in claim 7 is characterized in thatsoft water is used as the to-be-electrolyzed raw water supplied to theelectrolytic chamber when regenerating the cation-exchange membranewhile subjecting the to-be-electrolyzed raw water to the electrolysiswith a positive polarity.

Moreover, the invention set forth in claim 8 is characterized in thatdeionized water is used as the to-be-electrolyzed raw water supplied tothe electrolytic chamber when regenerating the cation-exchange membranewhile subjecting the to-be-electrolyzed raw water to the electrolysiswith a positive polarity.

Moreover, the invention set forth in claim 9 is characterized in thatthe to-be-electrolyzed raw water supplied to the electrolytic chamber isreplaced when regenerating the cation-exchange membrane while subjectingthe to-be-electrolyzed raw water to the electrolysis with a positivepolarity.

Furthermore, the invention set forth in claim 10 is characterized inthat the to-be-electrolyzed raw water supplied to the electrolyticchamber is replaced by circulating the to-be-electrolyzed raw water.

EFFECTS OF THE INVENTION

According to the invention set forth in claim 1, subjectingto-be-electrolyzed raw water to electrolysis with a positive polarity ina state where the to-be-electrolyzed raw water is supplied to theelectrolytic chamber allows desorption of the cations to regenerate thecation-exchange membrane, resulting in elimination of the contributingfactor preventing to steadily generate high-performance electrolyzedfunctional water. Therefore, the electrolyzed functional watergenerating apparatus can maintain a state allowing steady generation ofhigh-performance electrolyzed functional water.

According to the invention set forth in claim 2, since the currentdensity of the anode is set to a value exceeding a critical currentdensity or the lower limit that allows desorbing of the cations adsorbedinto the cation-exchange membrane as an electrolysis requirementnecessary for cation-exchange membrane regeneration throughelectrolysis, cation-exchange membrane regeneration through electrolysiscan be assuredly conducted.

According to the invention set forth in claim 3, the regenerating levelof the cation-exchange membrane is grasped based on changes in PH ofelectrolyzed functional water resulting from subjecting theto-be-electrolyzed raw water to the electrolysis with a positivepolarity over time. Therefore, provision of, for example, a pH sensor inthe electrolyzed functional water generating apparatus and thendetection of changes in PH over time while the to-be-electrolyzed rawwater is subjected to the electrolysis with a positive polarity allowfinding of the regenerating level of the cation-exchange membrane aswell as the performance of the resulting electrolyzed functional water.

According to the invention set forth in claim 4, since a reversedescaling process is provided, the scale adhesion problem of the cathodeand the disinfection and rinsing problem of the water flow path in theapparatus can be resolved at once. Furthermore, when in the situationwhere the cation-exchange membrane is exposed in a dry state, speedyrecovery of the functions of the apparatus may be implemented bycarrying out the reverse descaling process, thereby leading to excellentpractical advantages.

According to the invention set forth in claim 5, even if a large amountof cations adsorb into the cation-exchange membrane due to carrying outthe reverse descaling process, the membrane regenerating process iscarried out after the reverse descaling process, and thus the end desiremay be achieved by eliminating adverse affects from carrying out thereverse descaling process.

According to the invention set forth in claim 6, since the membranegenerating process is carried out intermittently, and an automaticmembrane regenerating process is carried out for five minutes everytwelve hours or for twenty-five minutes every thirty minutes even in acase where the apparatus is not used for a relatively long period suchas three days, regularly maintaining performance of the electrolyzedfunctional water generating apparatus at a high level is possible.Therefore, in the case of applying the performance maintaining methodaccording to the present invention to the electrolyzed functional watergenerating apparatus for domestic use, high-performance electrolyzedfunctional water can be provided immediately as needed. This allowsprovision of an apparatus with high customer satisfaction.

According to the invention set forth in claims 7 and 8, whenregenerating the cation-exchange membrane while subjecting theto-be-electrolyzed raw water to electrolysis with a positive polarity,soft water, more preferably deionized water is used as theto-be-electrolyzed raw water supplied to the electrolytic chamber,thereby improving membrane regeneration efficiency.

According to the invention set forth in claim 9, when regenerating thecation-exchange membrane while subjecting the to-be-electrolyzed rawwater to electrolysis with a positive polarity, the to-be-electrolyzedraw water supplied to the electrolytic chamber is replaced. Therefore,even if the cations within the water in the electrolytic chamber startto desorb from the cation-exchange membrane, membrane regenerationefficiency may be improved as a result of keeping the cationconcentration in the electrolytic chamber high.

According to the invention set forth in claim 10, since theto-be-electrolyzed raw water supplied to the electrolytic chamber isreplaced by circulating the to-be-electrolyzed raw water, as a result ofbeing able to regenerate the membrane while keeping the amount ofregenerating water to be used small, it may actively be utilized as awater resource.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic block diagram showing working parts of anelectrolyzed functional water generating apparatus;

FIG. 2 is a front view of an electrolytic cell deployed in theelectrolyzed functional water generating apparatus;

FIG. 3 is an A-A cross-sectional view of the electrolytic cell shown inFIG. 2;

FIG. 4 is a block diagram showing an electrical system of theelectrolyzed functional water generating apparatus;

FIG. 5 is a diagram showing the flow of water in a generating process;

FIG. 6 is a diagram showing the flow of water in a regenerating processand a rinsing process;

FIG. 7 is a simplified explanatory drawing focused on physical behaviorin an electrolytic chamber;

FIG. 8 is a simplified explanatory drawing focused on physical behaviorin the electrolytic chamber;

FIG. 9 is a simplified explanatory drawing focused on physical behaviorin the electrolytic chamber;

FIG. 10 is a simplified explanatory drawing focused on physical behaviorin the electrolytic chamber;

FIG. 11 is a simplified explanatory drawing focused on physical behaviorin the electrolytic chamber;

FIG. 12 is a simplified explanatory drawing focused on the physicalbehavior in the electrolytic chamber;

FIG. 13 is an external perspective view of an electrolyzed functionalwater generating apparatus according to the present invention;

FIG. 14 is a diagram showing an operation panel of the electrolyzedfunctional water generating apparatus according to the presentinvention;

FIG. 15 is a flowchart showing a main routine of a control unit mountedon the electrolyzed functional water generating apparatus according tothe present invention;

FIG. 16 is a flowchart showing a subroutine for generation activateprocessing;

FIG. 17 is a flowchart showing a subroutine for generation activateprocessing;

FIG. 18 is a flowchart showing a subroutine for rinse activateprocessing;

FIG. 19 is a flowchart showing a subroutine for operate processing(including generating processing);

FIG. 20 is a flowchart showing a subroutine for regenerating processing;

FIG. 21 is a flowchart showing a subroutine for rinsing;

FIG. 22 is a timing chart of a generating process;

FIG. 23 is a timing chart of a regenerating process;

FIG. 24 is a timing chart of a rinsing process;

FIG. 25 is a diagram describing how to exhibit performance ofelectrolyzed functional water due to electrolytic cell pressure droppingcharacteristics;

FIG. 26 is a diagram describing how critical current density changesaccording to changes in hardness of test water;

FIG. 27 is a diagram describing how critical current density changesaccording to changes in hardness of test water;

FIG. 28 is a diagram describing how critical current density changesaccording to changes in hardness of test water; and

FIG. 29 is a diagram showing a demonstration of suitable criticalcurrent densities.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Below, an embodiment of the present invention is described in detailbased on the appended drawings.

(System Structure)

First, a structure of an electrolyzed functional water generatingapparatus for domestic use according to the present invention isdescribed while referencing examples of FIGS. 1 through 4, 13 and 14.

FIG. 1 is a schematic block diagram showing working parts of anelectrolyzed functional water generating apparatus. FIG. 2 is a frontview of an electrolytic cell in the electrolyzed functional watergenerating apparatus. FIG. 3 is an A-A cross-sectional view of theelectrolytic cell shown in FIG. 2. FIG. 4 is a block diagram showing anelectrical system of the electrolyzed functional water generatingapparatus. FIG. 13 is an external perspective view of the electrolyzedfunctional water generating apparatus. FIG. 14 is a diagram showing anoperation panel of the electrolyzed functional water generatingapparatus.

An electrolyzed functional water generating apparatus 11 comprises awater storage tank 13, which retains to-be-electrolyzed raw water, apump 15 for discharging to-be-electrolyzed raw water retained in thewater storage tank 13 or a bottle B described later, an electrolyticcell 17, which electrolyzes the to-be-electrolyzed raw water dischargedfrom the pump 15, and a water tray 19 provided at the bottom thereof, asshown in FIGS. 1 and 13. Note that the electrolytic cell 17 is providedat the front part of the apparatus 11 so that the front part can be seenfrom the outside through an oblong window 18 provided on the front ofthe apparatus 11. This window 18 has a built-in acrylic resintransparent plate component 16. In addition, a detachable bottleconnector 21 is provided at the inner lower portion of the water storagetank 13 and connected to an attachment 20 fixed to the opening of thebottle B. Furthermore, a first pin electrode 23 (high-water levelsensor) is provided at a sidewall upper portion of the water storagetank 13 for detecting that the water retained in the water storage tank13 has reached a high-water level.

The water storage tank 13 and the pump 15 are connected via a firstwater supply channel 25 and structured to supply to the pump 15 theto-be-electrolyzed raw water retained in the bottle B or the waterstorage tank 13 via the first water supply channel 25. A second pinelectrode 27 (low-water level sensor and EC sensor) is provided midwayalong the first water supply channel 25 for detecting that the waterretained in the water storage tank 13 has reached a low-water level, anddetecting electric conductivity (EC) of the water flowing through thefirst water supply channel 25. Furthermore, a third pin electrode 29(low-water level sensor and EC sensor) is provided at a predeterminedinterval from the second pin electrode 27 midway along the first watersupply channel 25 for detecting the level of the water retained in thewater storage tank 13, and detecting electric conductivity (EC) of thewater flowing through the first water supply channel 25. The first pinelectrode 23, the second pin electrode 27, and the third pin electrode29 operate as a set for detecting the level of the water retained in thewater storage tank 13. More specifically, that set operates to detectthe water level by detecting whether or not there is conduction betweenthe third pin electrode 29, which is used as a common referenceelectrode, and the first pin electrode 23 or the second pin electrode27. In addition, the second pin electrode 27 and the third pin electrode29 operate as a pair of pin electrodes to detect the electricconductivity (EC) of the water flowing through the first water supplychannel 25. More specifically, the pair of pin electrodes operates tofind the electric conductivity (EC) through measurement of the electricresistance of a solution by applying a weak alternating voltage betweenthe pair of electrodes which are, for example, immersed in the solution.

The pump 15 and the electrolytic cell 17 are connected by a second watersupply channel 31 via an inflow pipe 32 provided on the inflow side ofthe electrolytic cell 17, and is structured so as to supply to theelectrolytic cell 17 the to-be-electrolyzed raw water discharged fromthe pump 15. A check valve 33 that prevents water back-flow is providedmidway along the second water supply channel 31. Note that a branch notshown in the drawing is formed along the second water supply channel 31on the electrolytic cell 17 side after the check valve 33, therebyallowing to-be-electrolyzed raw water to be supplied to the electrolyticcell 17 from the second water supply channel 31 via a pair of inflowpipes 32.

An outflow channel 35 for passing water flowing out from theelectrolytic cell 17 is connected to the electrolytic cell 17 via anoutflow pipe 34, which is provided on the outflow side of theelectrolytic cell 17, and an outlet 37 is provided at the other end ofthe outflow channel 35. An electromagnetic three-way valve 39 forselectively branching the flow of water through the outflow channel 35into either one of two routes is provided midway along the outflowchannel 35. Note that a branch not shown in the drawing is formedfurther on the electrolytic cell 17 side than the electromagneticthree-way valve 39 along the outflow channel 35, thereby allowingto-be-electrolyzed raw water to be transmitted to the outflow channel 35from the electrolytic cell 17 via a pair of outflow pipes 34. Acirculation path 41 is connected to the electromagnetic three-way valve39, and a circulatory water outlet 43 is provided at the other end ofthe circulation path 41 to let the water flow back towards the waterstorage tank 13. This allows water from the electrolytic cell 17 to flowback towards the water storage tank 13 via the electromagnetic three-wayvalve 39.

A schematic structure of the electrolytic cell 17 constituting a mainpart of the electrolyzed functional water generating apparatus 11 isdescribed forthwith. As shown in FIGS. 2 and 3, the electrolytic cell 17is constituted by a first casing 51 and a second casing 53 joined end toend sandwiching a sealing ring not shown in the drawings therebetween,and secured at the ends by joining means such as multiple bolts or nutsnot shown in the drawings. The electrolytic cell 17 has the pair ofinflow pipes 32 provided at the bottom of the first casing 51, and thepair of outflow pipes 34 provided at the top of the second casing 53. Anelectrolytic chamber 55 is formed in an internal space of theelectrolytic cell 17.

The first casing 51 and the second casing 53 constituting theelectrolytic cell 17 respectively have multiple hexagonal (some aretrapezoidal) window holes 57 formed apart from each other across theentire central portion when viewed from the front, as shown in FIG. 2.Electrode plates on the outside of the electrolytic chamber describednext are deployed so as to be seen through these window holes 57 fromthe outside of the electrolytic cell 17. A pair of first and secondcation-exchange membranes 59 and 60 separating the inside of theelectrolytic chamber 55 from the outside thereof is provided on eitherinner sidewall of the first casing 51 and the second casing 53. A pairof first and second electrode plates 61 and 62 is provided furtheroutward from the electrolytic chamber than the first and secondmembranes 59 and 60 in a state of being in contact with (adhered to) theentirety of the first and second membranes 59 and 60. A pair of thirdand fourth electrode plates 63 and 64 is provided inside theelectrolytic chamber 55 apart from the first and second membranes 59 and60 at a predetermined interval further inward the electrolytic chamberthan the first and second membranes 59 and 60 in order that the primarysurfaces respectively face to the first and second electrode plates 61and 62. In addition, a core frame 65 for supporting the third and fourthelectrode plates 63 and 64 is provided between these electrode plates 63and 64 in a state of being in contact with (adhered to) the entirety ofthe electrode plates 63 and 64. Although not shown in the drawing, notethat the core frame 65 is structured so as to be rigidly coupled withthe electrolytic cell 17 by having its ends sandwiched when joining thefirst casing 51 and the second casing 53 end to end. Furthermore,through-holes not shown in the drawing are formed at positions in thefirst and second electrode plates 61 and 62 and the first and secondcation-exchange membranes 59 and 60 corresponding to the pair of inflowpipes 32 or the pair of outflow pipes 34, and the pair of inflow pipes32 and the pair of outflow pipes 34 are provided passing through thesethrough-holes to the electrolytic cell 17. This allowsto-be-electrolyzed raw water to be supplied into the electrolyticchamber 55 via the pair of inflow pipes 32, and the to-be-electrolyzedraw water to be transmitted outside of the electrolytic chamber 55 viathe pair of outflow pipes 34.

The first through fourth electrode plates 61, 62, 63, and 64 areconnected to a direct current (DC) power source 67. Electrolytic voltagepolarities of these electrode plates are summarized for each operatingmode of the electrolyzed functional water generating apparatus 11forthwith. In a generating process for generating electrolyzedfunctional water and a membrane regenerating process for regeneratingthe cation-exchange membranes 59 and 60, a DC voltage from the DC powersource 67 is generally applied in a forward direction between a cathodeor the electrode plates 63 and 64 provided inside the electrolyticchamber 55 and an anode or the electrode plates 61 and 62 providedoutside the electrolytic chamber 55. Furthermore, in a reverse descalingprocess for descaling or a rinsing process for disinfecting and rinsingwetted parts in the apparatus, a DC voltage from the DC power source 67is generally applied with a reverse polarity between an anode or theelectrode plates 61 and 62 outside the electrolytic chamber 55 and acathode or the electrode plates 63 and 64 inside the electrolyticchamber 55.

The first through fourth electrode plates 61, 62, 63, and 64 used inthis embodiment are made of titanium, and a precious metal made from acombination of one or two or more selected from a group includingplatinum, iridium and palladium is sintered covering the entire surface.Hexagonal (some are trapezoidal) punched holes 69 are formed apart fromeach other across the entire central portions of the first throughfourth electrode plates 61, 62, 63, and 64 when viewed from the front,as shown in FIG. 2. This allows gas (hydrogen or oxygen), which isgenerated on the surfaces of the electrode plates 61 and 62 provided onthe outside of the electrolytic chamber 55, to escape to the backside ofthe membranes 59 and 60 (outside of the electrolytic chamber or into theatmosphere.) Note that the effective area of the electrode plates is 1dm²/plate.

Perfluorinated sulfonic acid membranes comprising a sulfonic acid groupas an electrolyte group may be preferably used as the cation-exchangemembranes 59 and 60 employed in this embodiment with consideration ofrespective contributing factors such as ion conductivity, physicalstrength, a gas barrier function, chemical stability, electrochemicalstability, thermal stability or the like. The Nafion™ membrane(registered trademark of DuPont), the Flemion™ membrane (registeredtrademark of Asahi Glass Co., Ltd.), the Aciplex™ F membrane (trademarkof Asahi Kasei Corporation) and the like or a copolymer membrane ofperfluoro vinylether and tetrafluoro ethylene including a sulfonic acidgroup are available as such membranes.

While with this type of perfluorinated sulfonic acid membrane, the shapethereof is maintained due to the crystallinity of the perfluoro alkylenechain, since it has an uncross-linked structure, flexibility of theelectrolyte group at the side chain is greater than that of a bridgedhydrocarbon electrolytic membrane. Therefore, a strong hydrophobic mainchain and a hydrophilic electrolyte group coexist in an ionized state,and the electrolyte group associates in a fluorocarbon matrix, formingion clusters. This ion cluster structure has approximately several-nmwide spherical clusters stringed together by narrow channels atapproximately 1 nm intervals.

The perfluorinated sulfonic acid membrane shows proton conductivity whenprotons are moving within water accumulated among the sphericalclusters. In other words, proton conductivity increases as thepercentage of water content in the membrane becomes high. On the otherhand, proton conductivity deteriorates as the percentage of watercontent in the membrane becomes low. Specifically, if the membrane iskept in a dry state, deterioration of proton conductivity progresses,film resistance increases, whereby electrolysis then becomes impossible.Therefore, it is important to keep the membrane from becoming dry.

Now, inter-plate distance between the pair of electrode plates 61 and 63or the pair of electrode plates 62 and 64 deployed respectively facingto each other sandwiching the cation-exchange membranes 59 and 60therebetween is appropriately selected to fall within a range of 0 mm to5.0 mm, more preferably approximately 1.2 mm to 1.5 mm. Here, aninter-plate distance of 0 mm assumes a case of using zero-gap electrodeswhere electrode membranes are directly formed on respective primarysurfaces of the cation-exchange membranes 59 and 60, or at a distanceequivalent to the thickness of the cation-exchange membranes 59 and 60.With zero-gap electrodes, an electrode film may be formed on either oneof the primary surfaces of the membranes 59 and 60. Meanwhile, althoughthe inter-plate distance between the electrode plates 63 and 64 providedin the electrolytic chamber 55 is not particularly limited, it isappropriately selected to fall within a range of 0.5 mm to 5 mm, morepreferably approximately 1 mm to 1.4 mm.

Next, a schematic structure of an electrical system of the electrolyzedfunctional water generating apparatus for domestic use according to aperformance maintaining method of the present invention is describedbased on FIGS. 4 and 14.

As shown in these drawings, a control apparatus 71 in the electrolyzedfunctional water generating apparatus 11 for domestic use comprises amicrocomputer (which may be referred to as ‘micon’ hereafter), whichcontrols the entire apparatus; the high-water level input unit(high-water level sensor) 23; the low-water level input unit (low-waterlevel sensor) 27; the EC input units (EC sensors) 27 and 29; a cellvoltage input unit 75, which detects and inputs residual voltage betweenelectrodes that were a cathode and an anode until just before stoppingelectrolysis while electrolysis is off; a generation switch (‘switch’ ishereafter referred to as ‘SW’) 77, which is for selecting anelectrolyzed functional water generating mode; a regeneration SW 79,which is for selecting a regenerating mode; and a rinse SW 81, which isfor selecting a mode of disinfecting and rinsing a water flow path and areverse descaling mode for electrode plates. The control apparatus 71further comprises the pump 15; a fan 85, which is for coolingheat-generating parts such as the DC power source 67 constituted by aswitching power source; the electromagnetic three-way valve 39; a buzzer87, which issues a vocal caution or warning for a user; an LED driver89, which drives various LEDs to blink; a generation LED 91, whichindicates a generating standby state by illuminating at a time whenwater in the water storage tank 13 exceeds at least the low-water level,and indicates to the effect that generation is in progress by blinkingwhen in the electrolyzed functional water generating mode; aregeneration LED 93, which indicates a regenerating standby state byilluminating at a time when water in the water storage tank 13 exceedsthe high-water level, and indicates to the effect that regeneration isin progress by blinking when in the regenerating mode; a rinse LED 95,which indicates a rinse standby state by illuminating at a time whenwater in the water storage tank 13 exceeds the high-water level, andindicates to the effect that rinsing is in progress by blinking when inthe rinse mode; a raw water hardness LED 97, which is constituted bymultiple (e.g., 5) LEDs and indicates hardness of the to-be-electrolyzedraw water by varying the blinking rate thereof; a remaining time LED 99,which counts down and displays in seven segments the remaining timeuntil operation termination when, for example, in either theregenerating mode or the rinse mode, and indicates in an identifiablemanner when an abnormal event occurs; a illumination LED101, whichdisplays an indication of performance of electrolyzed functional waterthat has just been generated; a polarity switching relay 103, whichdrives in conformity with a polarity switching instruction from themicroprocessor 73, and then outputs a polarity switching relay signal;and an electrolysis ON/OFF relay 105, which drives in conformity with anelectrolysis ON/OFF instruction from the microprocessor 73, and thenoutputs an electrolysis ON/OFF relay signal. The control apparatus 71further comprises a polarity reversal SW 107, which reverses voltagepolarity of an electrode plate of the electrolytic cell 17 that hasreceived the polarity switching relay signal from the polarity switchingrelay 103; an electrolysis ON/OFF SW 109, which receives theelectrolysis ON/OFF relay signal from the electrolysis ON/OFF relay 105and then switches electrolysis ON or OFF; and a discharging resistor111, which short circuits between electrodes that were a cathode and ananode until just before stopping electrolysis while electrolysis is offin order to discharge the residual voltage between the electrodes. Notethat the generation SW 77, the rinse SW 81, the generation LED 91, theregeneration LED 93, the rinse LED 95, the raw water hardness LED 97,and the remaining time LED 99 are provided on an operation panel 76, asshown in FIG. 14. The raw water hardness LED 97 may be structured so asto, for example, illuminate a yellow LED when the total hardness fallsbelow 30 ppm (warning that the hardness of the to-be-electrolyzed rawwater is low and inappropriate), illuminate a green LED when the totalhardness falls within the range of 30 to 300 ppm (inform that thehardness of the to-be-electrolyzed raw water is appropriate), andilluminate a red LED when the total hardness exceeds 300 ppm (warningthat the hardness of the to-be-electrolyzed raw water is high andinappropriate). More specifically, it may indicate the hardness of theto-be-electrolyzed raw water in stages by being constituted by threegreen LEDs so as to illuminate one green LED when the total hardnessfalls within the range of 30 to 60 ppm (inform that theto-be-electrolyzed raw water is soft water), illuminate two green LEDswhen the total hardness falls within the range of 60 to 120 ppm (informthat the to-be-electrolyzed raw water is medium water), and illuminatethree green LEDs when the total hardness falls within the range of 120to 300 ppm (inform that the to-be-electrolyzed raw water is hard water.)Furthermore, the illumination LED101 is constituted by, for example, sixblue LEDs, which are deployed at positions for illuminating the front ofthe electrolytic cell 17 from the surrounding thereof. However, asdescribed later, the illumination LED101 is controlled to varyilluminating duration and/or brightness based on the cell voltagefalling tendency after electrolysis is turned off. Accordingly, it isstructured to visually present to the user an indication of the state ofthe electrolytic cell 17 or performance of the electrolyzed functionalwater just generated.

(System Operation—Main Routine)

Next, operations of the electrolyzed functional water generatingapparatus 11 structured as such are described based on the flowchartshown in FIG. 15.

When power is supplied to the apparatus 11, values of various flags andtimers described later are initialized, whereby the apparatus 11 isready to start up (step 101, ‘step’ is hereafter referred to as ‘S’.)After this initialization, the microprocessor 73 carries out inputtingof information regarding respective SW input statuses such as whetherthe generation SW 77, for example, has been operated, the water levelinside the water storage tank 13, the electrical conductance (EC) of theto-be-electrolyzed raw water, and the like (S102), and carries outstatus determination of whether or not the apparatus 11 is operatingbased on these various pieces of information (S103).

If the apparatus 11 is determined not to be operating as a result of theoperating status determination in S103, the microprocessor 73 carriesout status determination of whether or not any one of the generation SW77, the regeneration SW 79, or the rinse SW 81 has been operated (S104,S105, and S106).

If any one of the above-given switches is determined to have beenoperated as a result of the switch operation input status determinationin S104, S105, and S106, the microprocessor 73 carries out generationactivate processing at the time that the generation SW 77 is operated(subroutine 1, ‘subroutine’ may hereafter be referred to as ‘Sub’),regeneration activate processing at the time that the regeneration SW 79is operated (Sub2,) and rinse activate processing at the time that therinse SW 81 is operated (Sub3) according to the operation input statusesof the various respective switches, and then carries out processing foreach mode (Sub4) after each subroutine has been executed.

If the switch operation input status determinations in S104, S105, andS106 show any one of the above-given switches has not been operated, themicroprocessor 73 blinks the various LEDs based on information regardingrespective SW operation input statuses input in S102, the water level ofinside the water storage tank 13, and the electrical conductance (EC) ofthe to-be-electrolyzed raw water and the like (S107). Afterwards,processing returns to S102, repeating the main routine of S102 throughS107 given forthwith.

On the other hand, if the operating status determination in S103 showsthat the apparatus 11 is operating, the microprocessor 73 continues tocarry out appropriate processing (Sub4). After execution of thissubroutine, processing proceeds to indicate processing (S107) of themain routine, repeating the main routine of S102 through S107 givenforthwith.

(System Operation—Sub1—Generation Activate Processing)

Next, generation activate processing of the Sub1 is described based onthe flowchart shown in FIG. 16.

Upon start of generation activate processing, the microprocessor 73carries out low-water level determination of whether or not the waterlevel in the water storage tank 13 has exceeded a low-water level(S111). The purpose of low-water level determination is to confirmwhether or not a prerequisite of the amount of to-be-electrolyzed rawwater at least exceeding the low-water level is satisfied underconsideration that accomplishing the end desire of generatingelectrolyzed functional water is impossible unless that amount ofto-be-electrolyzed raw water exists.

If the low-water level determination in S111 shows that the water levelhas exceeded the low-water level, the microprocessor 73 sets agenerating mode flag indicating that the operating mode of the apparatus11 is in generating mode (S122), makes the buzzer 87 sound a tonepattern 1 (PT1: ‘pi’, for example (sound a single short tone)) to notifythe user to the effect that the operating mode has been changed to thegenerating mode (S113), and then jumps to processing of the Sub4.

On the other hand, if the low-water level determination in S111 showsthat the water level has not exceeded the low-water level, themicroprocessor 73 makes the buzzer 87 sound a tone pattern 2 (PT2: ‘pipi pi’, for example (intermittently sound three consecutive shorttones)) to notify the user to the effect that the operating mode has notbeen changed to the generating mode (S113), and then jumps to processingof the Sub4.

(System Operation—Sub2—Regeneration Activate Processing)

Next, regeneration activate processing of the Sub2 is described based onthe flowchart shown in FIG. 17.

Upon start of regeneration activate processing, the microprocessor 73carries out high-water level determination of whether or not the waterlevel in the water storage tank 13 has exceeded a high-water level(S121). The purpose of high-water level determination is to confirmwhether or not a prerequisite of the amount of to-be-electrolyzed rawwater at least exceeding the high-water level is satisfied underconsideration that accomplishing the end desire of regenerating acathode-exchange membrane and a negative plate during positive polarityelectrolysis is impossible unless that amount of to-be-electrolyzed rawwater exists.

If the high-water level determination in S121 shows that the water levelhas exceeded the high-water level, the microprocessor 73 sets aregenerating mode flag indicating that the operating mode of theapparatus 11 is in regenerating mode (S122), sets the regeneratingrequired time (e.g., 5 min. in this embodiment) to a regeneration timerT1 constituted by a countdown timer, for example (S123), sounds a tonepattern 1 (PT1: ‘pi’, for example (sounds a single short tone)) tonotify the user to the effect that the operating mode has been changedto the regenerating mode (S124), and then jumps to processing of theSub4.

On the other hand, if the high-water level determination in S121 showsthat the water level has not exceeded the high-water level, themicroprocessor 73 makes the buzzer 87 sound a tone pattern 2 (PT2: ‘pipi pi’, for example (intermittently sound three consecutive shorttones)) to notify the user to the effect that the operating mode has notbeen changed to the generating mode (S125), and then jumps to processingof the Sub4.

(System Operation—Sub3—Rinse Activate Processing)

Next, rinse activate processing of the Sub3 is described based on theflowchart shown in FIG. 18.

Upon start of rinse activate processing, the microprocessor 73 carriesout high-water level determination of whether or not the water level inthe water storage tank 13 has exceeded the high-water level (S131). Thepurpose of high-water level determination is to confirm whether or not aprerequisite of the amount of to-be-electrolyzed raw water at leastexceeding the high-water level is satisfied under consideration thataccomplishing the end desire of disinfecting and rinsing wetted parts inthe apparatus 11 is impossible unless that amount of to-be-electrolyzedraw water exists.

If the high-water level determination in S131 shows that the water levelhas exceeded the high-water level, the microprocessor 73 sets a rinsingmode flag indicating that the operating mode of the apparatus 11 is inthe rinsing mode (S132), sets the time required (e.g., 10 min. in thisembodiment) for disinfecting and rinsing the wetted parts in theapparatus 11 to a rinse timer T2 constituted by a countdown timer, forexample (S133), makes the buzzer tone a tone pattern 1 (PT1: ‘pi’, forexample (sound a single short tone)) to notify the user to the effectthat the operating mode has been changed to the rinsing mode (S134), andthen jumps to processing of the Sub4.

On the other hand, if the high-water level determination in S131 showsthat the water level has not exceeded the high-water level, themicroprocessor 73 makes the buzzer 87 sound a tone pattern 2 (PT2: ‘pipi pi’, for example (intermittently sound three consecutive shorttones)) to notify the user to the effect that the operating mode has notbeen changed to the rinsing mode (S135), and then jumps to processing ofthe Sub4.

(System Operation—Sub 4—Processing-Generating Processing)

Next, processing of the Sub4 is described based on the flowchart shownin FIG. 19.

Upon start of processing, the microprocessor 73 carries out operatingmode determination of whether either generating, regenerating, orrinsing is in progress based on the set status of the respective variousmode flags (generating, regenerating, and rinsing) (S141, S142, S143).

If the operating mode determinations in S141, S142, and S143 shows thatany one of the above-given operating modes is in progress, themicroprocessor 73 carries out generating after S144 when it isdetermined that generating is in progress, regenerating when it isdetermined that regenerating is in progress (Sub5), and rinsing when itis determined that rinsing is in progress (Sub6). After execution ofeach subroutine program, processing returns to indicate processing(S107) of the main routine shown in FIG. 15.

On the other hand, if the operating mode determinations in S141, S142,and S143 show that none of the above-given operating modes areappropriate, the microprocessor 73 returns processing to indicateprocessing (S107) of the main routine shown in FIG. 15.

However, if the operating mode determination in S141 shows thatgenerating is in progress, the microprocessor 73 carries out statusdetermination of whether or not the generation SW 77 has been operated(S144).

If the switch input status determination in S144 shows that thegeneration SW 77 has been operated, the microprocessor 73 carries outlow-water level determination of whether or not the water level in thewater storage tank 13 has exceeded the low-water level (S145), while ifit is determined that the generation SW 77 has not been operated, themicroprocessor 73 carries out generation terminating (S148).

If the low-water level determination in S145 shows that water level hasexceeded the low-water level, the microprocessor 73 carries outprocessing for continuing operation in generating mode as the operatingmode of the apparatus 11 (S145). After this operation, processingreturns to indicate processing (S107) of the main routine shown in FIG.15.

On the other hand, if the low-water level determination in S145 showsthat the water level has not exceeded the low-water level, themicroprocessor 73 makes the buzzer 87 sound a tone pattern 3 (PT3:‘pi-’, for example (sound a single long tone)) to notify the user to theeffect of an attention attracting status (insufficient amount ofto-be-electrolyzed raw water) (S147), and then carries out generationterminating (S148). Once generating is terminated, performance indicateprocessing is carried out (S149) and then processing returns to indicateprocessing (S107) of the main routine shown in FIG. 15.

Here, performance indicate processing of S149 is processing for visuallypresenting to the user the status of the electrolytic cell 17, namelyperformance of the electrolyzed functional water just generated byvarying illuminating duration and/or brightness of the illuminationLED101, which illuminates the front of the electrolytic cell 17 from thesurrounding thereof, based on the cell voltage falling tendency afterelectrolysis is turned off. Introducing the background of thisperformance indicating technology, the inventors have found a certainrelationship between the cell voltage falling tendency afterelectrolysis is turned off and the performance of the electrolyzedfunctional water just generated, and applying this development may allowrough indication of the performance of the electrolyzed functional waterjust generated be indicated. Here, this certain relationship means arelationship where cell voltage falling tendency after electrolysis isturned off is gradual (duration from 1.65V or cell voltage immediatelyafter electrolysis is turned off falling to 1V is thirty seconds) whenthe electrolyzed functional water is in a normal state (hydrogenconcentration is high), whereas cell voltage falling tendency afterelectrolysis is turned off is more sudden than the former (duration from1.65V or cell voltage immediately after electrolysis is turned offfalling to 1V is five seconds) when the electrolyzed functional water isin a performance impaired state (hydrogen concentration is low), asshown in the example of FIG. 25. Note that in the example shown in FIG.25, a load of 100 ohms is employed as the discharging resistor 111.Furthermore, to easily carry out performance evaluation of theelectrolyzed functional water (determine hydrogen concentration), oftechnologies filed and already disclosed by the applicants in additionto the above-described performance indicating function, a method ofanalyzing dissolved hydrogen concentration through oxidation-reductiontitration of an oxidation-reduction pigment (e.g., methylene blue)disclosed in International Publication No. WO2003/002466 should beemployed.

(System Operation—Sub5—Regenerating)

Next, regenerating in the Sub5 is described based on the flowchart shownin FIG. 20.

Upon start of regenerating, the microprocessor 73 carries out statusdetermination of whether or not the regeneration SW 79 has been operated(S151).

If the switch operation input status determination in S151 shows thatthe regeneration SW 79 is not operating, the microprocessor 73 carriesout high-water level determination of whether or not the water level inthe water storage tank 13 has exceeded the high-water level (S152),while if it is determined that the regeneration SW 79 has been operated(the regeneration SW 79 has been operated while regeneration is inprogress; such operating occurs when the user wants to manuallyterminate regeneration), buzzer tone: PT1 processing (S155) is carriedout. In other words, in S155, the microprocessor 73 makes the buzzer 87sound the tone pattern 1 (PT1: ‘pi-’, for example (sound a single longtone)) to notify the user to the effect of having accepted manualtermination of regeneration (S155), and then carries out terminating ofregeneration (S157). Once regenerating is terminated, processing returnsto indicate processing (S107) of the main routine shown in FIG. 15.

If the high-water level determination of S152 shows that the water levelhas not exceeded the high-water level, the microprocessor 73 carries outthe aforementioned regeneration terminating (S157) assuming that anunforeseen event such as a water leak has occurred, while if it isdetermined that the water level has exceeded the high-water level, themicroprocessor 73 carries out regenerating time elapse determination ofwhether or not time required (e.g., 5 min. in this embodiment) foraccomplishing regeneration of the cation-exchange membrane set to theregeneration timer T1 has elapsed (S153).

If the regenerating time elapse determination of S153 shows that theregenerating required time has elapsed, the microprocessor 73 carriesout buzzer tone: PT3 processing (S156), while if it is determined thatthe regenerating time has not elapsed, the microprocessor 73 carries outprocessing for continuing processing in regenerating mode as theoperating mode of the apparatus 11 (S154). Afterwards, processingreturns to indicate processing (S107) of the main routine shown in FIG.15. Note that in S156, the microprocessor 73 makes the buzzer 87 soundthe tone pattern 3 (PT3: ‘pi-’, for example (sound a single long tone))to notify the user to the effect of an attention attracting status(automatic termination of the regenerating mode) (S156), and thencarries out the aforementioned regeneration terminating (S157).

(System Operation—Sub6—Rinsing)

Next, rinsing in the Sub6 is described based on the flowchart shown inFIG. 21.

Upon start of rinsing, the microprocessor 73 carries out statusdetermination of whether or not the rinse SW 81 has been operated(S161).

If the switch input status determination in S161 shows that the rinse SW81 has not been operated, the microprocessor 73 carries out high-waterlevel determination of whether or not the water level in the waterstorage tank 13 has exceeded the high-water level (S162), while if it isdetermined that the rinse SW 81 is operating (the rinse SW 81 isoperating while rinsing is in progress; such operating occurs when theuser wants to manually terminate rinsing), buzzer tone: PT1 processing(S165) is carried out. In other words, in S165, the microprocessor 73makes the buzzer 87 sound the tone pattern 1 (PT1: ‘pi-’, for example(sound a single long tone)) to notify the user to the effect of havingaccepted manual termination of rinsing (S165), and then carries outrinse terminating (S157). Once rinsing is terminated, processing returnsto indicate processing (S107) of the main routine shown in FIG. 15.

If the high-water level determination in S162 shows that the water levelhas not exceeded the high-water level, the microprocessor 73 carries outthe aforementioned rinse terminating (S167) assuming that an unforeseenevent such as a water leak has occurred, while if it is determined thatthe water level has exceeded the high-water level, the microprocessor 73carries out rinsing time elapse determination of whether or not timerequired (e.g., 10 min. in this embodiment) for accomplishingdisinfecting and rinsing of wetted parts in the apparatus 11 set to therinse timer T2 has elapsed (S163).

If the rinsing time elapse determination in S163 shows that the rinsingtime has elapsed, the microprocessor 73 carries out buzzer tone: PT3processing (S166), while if it is determined that the rinsing requiredtime has not elapsed, the microprocessor 73 carries out processing forcontinuing processing in the rinsing mode as the operating mode of theapparatus 11 (S164). Afterwards, processing returns to indicateprocessing (S107) of the main routine shown in FIG. 15. Note that inS166, the microprocessor 73 makes the buzzer 87 sound the tone pattern 3(PT3: ‘pi-’, for example (sound a single long tone)) to notify the userto the effect of an attention attracting status (automatic terminationof the rinsing mode) (S166), and then carries out the aforementionedrinse terminating (S167).

Usage and operation of the electrolyzed functional water generatingapparatus 11 structured in this manner are described divided into anelectrolyzed functional water generating process, a regenerating processfor the cation-exchange membranes 59 and 60, and a rinsing process forthe electrode plates (negative plates) while referencing the appendeddrawings. A timing chart for the generating process is given in FIG. 22,a timing chart for the regenerating process is given in FIG. 23, and atiming chart for the rinsing process is given in FIG. 24.

(Generating Process)

To generate electrolyzed functional water using the electrolyzedfunctional water generating apparatus 11, as shown with the flow of thegenerating process of FIG. 5, to begin with, the cap of (PET) bottledwater such as commercially available mineral water, for example, isopened and an attachment 20 is then fixed to the opening thereof. Next,the bottle B is turned upside down and the attachment 20 is insertedtowards a bottle connector 21 positioned at the lower portion of thewater storage tank 13 to connect the attachment 20 and the bottleconnector 21, and thereby preparing to carry out the generating process.At this time, if the user manipulates the generation SW 77 to input,operation begins in the generating mode, to-be-electrolyzed raw water inthe bottle B is fed into the electrolytic cell 17 when the pump 15 isdriven, and electrolysis processing of the to-be-electrolyzed raw waterin the electrolytic cell 17 is carried out.

In such generating process, how the various switches, the various LEDs,and the various actuators such as the pump 15, the fan 85, theelectromagnetic three-way valve 39, the buzzer 87, and the relays 103and 105 operate by association is described in detail while referencingFIG. 22.

To begin with, in the case where the high-water level is not exceeded(the generation LED 91 is not illuminated in this case), generating doesnot start even if the user manipulates the generation SW 77 to input. Atthis time, the buzzer 87 sounds the tone pattern 2 (PT2: ‘pi pi pi’, forexample (intermittently sounds three consecutive short tones)) to warnthe user that the operating mode could not change to the generatingmode.

Meanwhile, in the case where the low-water level is exceeded (thegeneration LED 91 is illuminated in this case), generating starts whenthe user manipulates the generation SW 77 to input. At this time, thebuzzer 87 sounds the tone pattern 1 (PT1: ‘pi’, for example (sounds asingle short tone)) to notify the user that the operating mode haschanged to the generating mode. Generating continues only while the userkeeps pressing the generation SW 77 under the condition of the amount ofwater exceeding the low-water level. When the water level falls belowthe low-water level while the user continues to press the generation SW77, the buzzer 87 sounds the tone pattern 3 (PT3: ‘pi-’, for example(sounds a single long tone)) to notify the user to the effect of anattention attracting status (insufficient amount of to-be-electrolyzedraw water).

Operations of the various LEDs and the various actuators such as thepump 15, the fan 85, the electromagnetic three-way valve 39, the buzzer87, and the relays 103 and 15 while generating is in progress aredescribed forthwith. The generation LED 91 blinks to notify the user tothe effect that operation is in progress in the generating mode. The fan85 continues to blow air while generating is in progress and untilthirty seconds have elapsed after termination thereof. Theelectromagnetic three-way valve 39 is switched-over to the outflow side.The pump 15 is driven to discharge the to-be-electrolyzed raw water. Theelectrolysis ON/OFF relay 105 is biased to the positive electrode side.The illumination LED101 continues illuminating by being applied with aspecified power (normal mode) while generating is in progress. On theother hand, after generating is turned off, the illumination LED101illuminates by being controlled to vary illuminating duration and/orbrightness based on the cell voltage falling tendency after electrolysisis terminated. Furthermore, the raw water hardness LED 97 indicateshardness, which is calculated by the microprocessor 73 based on ECvalues of the to-be-electrolyzed raw water detected by the EC inputunits (EC sensors) 27 and 29, by varying the blinking rate thereof.

Next, properties and applications of the electrolyzed functional waterare described with focus on electrode reactions in the generatingprocess. If to-be-electrolyzed raw water is subjected to electrolysiswith a positive polarity in a state where the to-be-electrolyzed rawwater is supplied to the electrolytic chamber 55, an electrochemicalreaction represented by the reaction formula

4H₂O+4e ⁻→2H₂↑4OH⁻

occurs on the surfaces of the cathodes 63 and 64 provided in theelectrolytic chamber 55, generating hydrogen and hydroxide ions, and asa result of the generated hydrogen dissolving in the water, electrolyzedhydrogen-dissolved water is generated. Meanwhile, an electrochemicalreaction represented by the reaction formula:

2H₂O→O₂↑4H⁺+4e ⁻

occurs on the surfaces of the anodes 61 and 62 provided in contact withthe cation-exchange membranes 59 and 60, or more specifically, betweenthe anode 61 and the cation-exchange membrane 59 and also between theanode 62 and the cation-exchange membrane 60, generating hydroxide andhydrogen ions.

Since all of the abundant hydrogen ions generated in this manner passthrough the cation-exchange membranes 59 and 60 and are reduced to watermolecules through an equivalent weight reaction occurring with thehydroxide ions generated on the surfaces of the cathodes 63 and 64, thepH of the generated electrolyzed functional water in the electrolyticchamber 55 is maintained at almost the same pH as the raw water. Inother words, electrolyzed hydrogen-saturated water (electrolyzedfunctional water) in which abundant minute hydrogen bubbles generatedthrough electrolysis are dissolved is provided almost maintaining the pHof the raw water. The electrolyzed functional water generated in thismanner is retrieved from the outlet 37 and is used for drinking, forexample.

(Regenerating Process)

When electrolyzing performance of the electrolytic cell 17 andperformance of the electrolyzed functional water are impaired, theregenerating process is carried out for the purpose of descaling thethird and fourth electrode plates 63 and 64 used as cathodes duringpositive polarity electrolysis, and regeneration of the cation-exchangemembranes 59 and 60. Note that with the present invention, the processfor regenerating the cation-exchange membranes 59 and 60 is called amembrane regenerating process (synonymous to the membrane regeneratingprocess referred to in the appended claims), and is distinguished fromthe above-given regenerating process for regenerating the electrodeplates and the cation-exchange membranes.

To carry out the regenerating process, as shown in FIG. 6, to beginwith, for example, tap water, preferably soft water, more preferablydeionized water is poured in the water storage tank 13 until exceedingthe high-water level, and thereby preparing to carry out theregenerating process. At this time, if the user manipulates theregeneration SW 79 to input, operation begins in the regenerating mode,to-be-electrolyzed raw water in the water storage tank 13 is fed intothe electrolytic cell 17 by driving the pump 15 in a predeterminedsequence, and electrolysis of the to-be-electrolyzed raw water in theelectrolytic cell 17 is carried out. Here, in the membrane regeneratingprocess, it is important to carry out electrolysis under an electrolysisrequirement of exceeding a certain critical current density (e.g., 2A/dm²) or the lower limit in order to desorb cations adsorbed into thecation-exchange membranes 59 and 60.

How various switches, various LEDs, and various actuators such as thepump 15, the fan 85, the electromagnetic three-way valve 39, the buzzer87, and the relays 103 and 105 operate by association in suchregenerating process is described in detail while referencing FIG. 23.

To begin with, in the case where the high-water level is not exceeded(the regeneration LED 93 is not illuminated in this case), regeneratingdoes not start even if the user manipulates the regeneration SW 79 toinput. At this time, the buzzer 87 sounds the tone pattern 2 (PT2: ‘pipi pi’, for example (intermittently sounds three consecutive shorttones)) to warn the user that the operating mode could not change to theregenerating mode.

Meanwhile, in the case where the high-water level is exceeded (theregeneration LED 93 is illuminated in this case), regenerating startswhen the user manipulates the regeneration SW 79 to input. At this time,the buzzer 87 sounds the tone pattern 1 (PT1: ‘pi’, for example (soundsa single short tone)) to notify the user that the operating mode haschanged to the regenerating mode. Regenerating continues until a presetregenerating time (e.g., 5 min. in this embodiment) has elapsed or theuser manipulates the regeneration SW 79 to input (manually terminatesregeneration) under the condition that the high-water level is exceeded.While regenerating is in progress, when an unforeseen event such as awater leak occurs and the water level falls below the high-water level,the regenerating time has elapsed, or there has been an input from theregeneration SW 79, the buzzer 87 sounds the tone pattern 3 (PT3: ‘pi-’,for example (sounds a single long tone)) to notify the user to theeffect of an attention attracting status (termination of regenerating)and regeneration is then terminated.

Operations of the various LEDs and the various actuators such as thepump 15, the fan 85, the electromagnetic three-way valve 39, the buzzer87, and the relays 103 and 105 while regeneration operating is inprogress are described forthwith. The regeneration LED 93 blinks tonotify the user to the effect that operation is in progress in theregenerating mode. The fan 85 continues to blow air while regeneratingis in progress and until sixty seconds have elapsed after terminationthereof. The electromagnetic three-way valve 39 is switched-over to acirculation side. The pump 15 stops until twenty seconds have elapsedimmediately after regenerating has started. On the other hand, afterthose twenty seconds thereafter has elapsed (remaining time is 280seconds), it intermittently drives (drive thirty seconds and rest threeseconds) repeatedly to intermittently discharge the to-be-electrolyzedraw water. The electrolysis ON/OFF relay 105 is biased to the reversepolarity electrolysis side (descale the negative plates 63 and 64 duringpositive polarity electrolysis) until twenty seconds have elapsedimmediately after regenerating has started, and then after a ten-secondduration of no electrolysis, it is biased to the positive polarityelectrolysis side for only 270 seconds (regeneration of thecation-exchange membranes 59 and 60.) The polarity switching relay 103is biased to the reverse polarity electrolysis side until twenty secondshave elapsed immediately after regenerating has started. Here, observingthe timing chart for the electrolysis ON/OFF relay 105 and the polarityswitching relay 103, during the duration until twenty seconds haveelapsed immediately after regenerating has started, reverse electrolysisis conducted while the pump 15 is not driven. This is for the purpose ofsuppressing the amount of hardness components adsorbed in thecation-exchange membranes 59 and 60. This is because if a reversedescaling process is carried out while driving the pump 15 using watercontaining hardness components such as tap water as water to beregenerated, adsorption of the hardness components in thecation-exchange membranes 59 and 60 accelerates as a result of thecation-exchange membranes 59 and 60 being continuously exposed tocations successively supplied thereto. Then, the remaining time LED 99counts down and displays the remaining time until the automaticregenerating process is complete.

Next, action mechanism of the membrane regenerating process (same withthe generating process) is described while referencing FIGS. 7 through10 focusing on behaviors of materials in the electrolytic chamber 55 bycategorizing them into categories based on whether electrolysis isconducted or not, and categories in pH of electrolyzed water that isacidic, alkaline, or neutral.

FIGS. 7 through 10 are simplified explanatory diagrams of just the lefthalf of the electrolytic chamber 55 focusing on behaviors of thematerials therein.

To begin with, a case of no electrolysis is described while referencingFIG. 7. If the apparatus 11 is left in an electrolysis off state,adsorption of cations such as calcium ions or magnesium ions existing inthe residual water in the electrolytic chamber 55 to the membrane 60gradually progresses at the same time that hydrogen ions are dischargeddue to substitution by the cations. At this time, focusing oncharacteristics of the residual water in the electrolytic chamber 55,the hardness thereof reduces and the pH thereof becomes more acidic. Theadsorption progression rate of the cations to the membrane 60 graduallyslows down as the mutual relationship between parameters such ashardness of the residual water in the electrolytic chamber 55, theadsorption rate of cations to the membrane 60, and pH of the residualwater approaches a state of equilibrium, and the progression ofadsorption may stop at the point when a state of equilibrium isachieved.

Next, a case of positive polarity electrolysis and an acidic pH of theelectrolyzed water is described while referencing FIG. 8. In this case,since the adsorption progression rate of the cations to the membrane 60tends to increase (tends to accumulate), adsorption of the cationsexisting within the water in the electrolytic chamber 55 to the membrane60 increases at the same time that the hydrogen ions are discharged dueto substitution by the cations, and supply of hydrogen ions generated atthe anode to the water in the electrolytic chamber 55 by permeating themembrane gradually progresses. At this time, focusing on characteristicsof the water in the electrolytic chamber 55, the hardness thereofreduces and the pH thereof becomes more acidic, as with the example ofFIG. 7. As an applicable example, there may be a case where electrolysisis conducted under an electrolysis requirement not satisfying thecritical current density in a state where adsorption of the cations tothe membrane 60 is not progressing much.

Next, a case of positive polarity electrolysis with an alkaline pH ofthe electrolyzed water is described while referencing FIG. 9. In thiscase, since the adsorption progression rate of the cations to themembrane 60 tends to decrease (tends to discharge), discharge of thecations accumulated in the membrane 60 gradually progresses due tosubstitution by the hydrogen ions. At this time, focusing oncharacteristics of the water in the electrolytic chamber 55, thehardness thereof increases and the pH thereof becomes more alkaline. Asan applicable example, there may be a case where electrolysis isconducted under an electrolysis requirement exceeding the criticalcurrent density in a state where adsorption of the cations to themembrane 60 is excessive.

Next, a case of positive polarity electrolysis having a neutral pH ofthe electrolyzed water is described while referencing FIG. 10. In thiscase, since the adsorption progression rate of the cations to themembrane 60 is in a state of equilibrium (tends to be neutral), andsince all of the hydrogen ions generated at the anode pass through thecation-exchange membrane 60 and are reduced to water molecules throughan equivalent weight reaction occurring with the hydroxide ionsgenerated on the surface of the cathode 64, the pH of the generatedelectrolyzed functional water in the electrolytic chamber 55 ismaintained at almost the same pH as the raw water. As an applicableexample, there may be a case where electrolysis is conducted under anelectrolysis requirement exceeding the critical current density in astate where the membrane regeneration level is ideal.

(Rinsing Process)

When the apparatus 11 is not used for a relatively long time such as aweek, a rinsing process is carried out for the purpose of disinfectionand rinsing of wetted parts in the apparatus 11, regeneration of thecation-exchange membranes 59 and 60, and descaling of the third andfourth negative plates 63 and 64 during positive polarity electrolysis.Note that with the present invention, the process for descaling thenegative plates 63 and 64 during positive polarity electrolysis iscalled a reverse descaling process (synonymous to the reverse descalingprocess referred to in the appended claims), and is distinguished fromthe above-given rinsing process for regenerating the wetted parts andthe cation-exchange membranes in the apparatus 11 and rinsing theelectrode plates.

To carry out the rinsing process, as shown in FIG. 6 (since flow ofwater in the rinsing process is the same as that of the regeneratingprocess, the diagrams showing the flow of water in the regeneratingprocess are used in common), to begin with, for example, tap water,preferably soft water, more preferably deionized water is poured in thewater storage tank 13 until exceeding the high-water level, and therebypreparing to carry out the rinsing process. At this time, if the usermanipulates the rinse SW 81 to input, operation begins in the rinsemode, to-be-electrolyzed raw water in the water storage tank 13 is fedinto the electrolytic cell 17 by driving the pump 15 in a predeterminedsequence, and electrolysis of the to-be-electrolyzed raw water in theelectrolytic cell 17 is carried out.

How various switches, various LEDs, and various actuators such as thepump 15, the fan 85, the electromagnetic three-way valve 39, the buzzer87, and the relays 103 and 105 operate by association in such rinsingprocess is described in detail while referencing FIG. 24.

To begin with, in the case where the high-water level is not exceeded(the rinse LED 95 is not illuminated in this case), rinsing does notstart even if the user manipulates the rinse SW 81 to input. At thistime, the buzzer 87 sounds the tone pattern 2 (PT2: ‘pi pi pi’, forexample (intermittently sounds three consecutive short tones)) to warnthe user that the operating mode could not change to the rinsing mode.

Meanwhile, in the case where the high-water level is exceeded (the rinseLED 95 is illuminated in this case), automatic rinsing starts when theuser manipulates the rinse SW 81 to input. At this time, the buzzer 87sounds the tone pattern 1 (PT1: ‘pi’, for example (sounds a single shorttone)) to notify the user, that the operating mode has changed to therinsing mode. Rinsing continues until a preset rinsing time (e.g., 10min. in this embodiment) has elapsed or the user manipulates the rinseSW 81 to input (manual rinse operating termination) under the conditionthat the high-water level is exceeded. While rinsing is in progress,when an unforeseen event such as a water leak occurs and the water levelfalls below the high-water level, the rinsing time has elapsed, or thereis an input from the rinse SW 81, the buzzer 87 sounds the tone pattern3 (PT3: ‘pi-’, for example (sounds a single long tone)) to notify theuser to the effect of an attention attracting status (termination ofrinsing), and rinsing is then terminated.

Operations of the various LEDs and the various actuators such as thepump 15, the fan 85, the electromagnetic three-way valve 39, the buzzer87, and the relays 103 and 15 while rinsing is in progress are describedforthwith. The rinse LED 95 blinks to notify the user to the effect thatoperation is in progress in the rinsing mode. The fan 85 continues toblow air while rinsing is in progress and until sixty seconds haveelapsed after termination thereof. The electromagnetic three-way valve39 is switched-over to the circulation side. The pump 15 intermittentlydischarges the to-be-electrolyzed raw water by repeating beingintermittently driven (drive thirty seconds and rest three seconds)until 590 seconds have elapsed immediately after rinsing has started,and stops for the remaining ten seconds. The electrolysis ON/OFF relay105 is biased to the reverse polarity electrolysis side until twentyseconds have elapsed from the point when fifteen seconds have elapsedafter rinsing has started. After this, a 265-second duration of noelectrolysis follows. Next, the electrolysis ON/OFF relay 105 is biasedto the reverse polarity electrolysis side for only 280 seconds(regeneration of the cation-exchange membranes 59 and 60). After this, aten-second duration of no electrolysis follows. Next, the electrolysisON/OFF relay 105 is biased to the reverse polarity electrolysis side foronly ten seconds. Note that the reason why fifteen seconds of delay timeis provided before switching the electrolysis ON/OFF relay 1050Nimmediately after rinsing has started is for making the sodium chlorideconcentration in the to-be-electrolyzed raw water uniform by stirringthat solution when using a sodium chloride solution, for example, as theto-be-electrolyzed raw water for rinsing. The polarity switching relay103 is biased to the reverse polarity electrolysis side until twentyseconds have elapsed from the point when fifteen seconds have elapsedafter rinsing has started and just for ten seconds from the point when590 seconds have elapsed after rinsing has started. Here, of the reverseelectrolysis performed twice, the former is mainly carried out forconverging the pH of the rinsing water into a range (pH 4 to 6) allowingincrease in sterilizing capability of hypochlorous acid, and the latteris mainly for descaling the third and fourth electrode plates 63 and 64,which are used as cathodes during positive polarity electrolysis. Then,the remaining time LED 99 counts down and displays the remaining timeuntil the automatic rinsing process is complete.

Next, the developing mechanism of the scale adhesion problem, and theaction mechanism of the rinsing process for resolving such a problem aredescribed while referencing FIGS. 11 and 12 with focus on the behaviorsof the materials in the electrolytic chamber 55.

FIGS. 11 and 12 are simplified explanatory diagrams of just the lefthalf of the electrolytic chamber 55 focusing on behaviors of thematerials therein.

To begin with, the developing mechanism of the scale adhesion problem isdescribed while referencing FIG. 11. When operating in the generatingprocess, for example, continues for a long time, as with the example ofFIG. 10, electrolyzed hydrogen-saturated water (electrolyzed functionalwater) in which abundant minute hydrogen bubbles generated throughelectrolysis are dissolved is provided almost maintaining the pH of theraw water as is. However, since the calcium ions and magnesium ionsexisting within the water in the electrolytic chamber 55 react with thehydroxide ions on the surface of the cathode 64, calcium hydroxide andmagnesium hydroxide precipitate on that surface. Such scale adhesion onthe surface of the cathode 64 causes deterioration of the electrolysisefficiency.

At this point, in order to resolve this scale adhesion problem, thepresent invention employs the rinsing process in which a DC voltage fromthe DC power source 67 is applied in a reverse direction between ananode or the electrode plate 64 provided inside the electrolytic chamber55 and a cathode or the electrode plate 62 provided outside theelectrolytic chamber 55.

As shown in FIG. 12, when the reverse descaling process is carried out,the adsorption progression rate of the cations to the membrane 60increases and discharge of hydrogen ions progresses due to substitutionby the cations since the electrode plate 63 provided in contact with thecation-exchange membrane 60 is the cathode. In addition, since theelectrode plate 64 in the electrolytic chamber 55 is the anode, supplyof the hydrogen ions generated on the surface of this anode 64 to thewater in the electrolytic chamber 55 gradually progresses. At this time,focusing on characteristics of the water in the electrolytic chamber 55,the hardness thereof decreases and the pH thereof becomes more acidic.Note that the hydroxide ions generated between the cathode 62 and themembrane 60 cannot pass through the cation-exchange membrane 60,accumulating in the vicinity of the cathode 62. Furthermore, in therinsing process, if water containing chlorine ions is employed as theto-be-electrolyzed raw water, or chlorine ions are aggressively suppliedby dissolving a chloride such as sodium chloride or potassium chloridein the to-be-electrolyzed raw water, hypochlorous acidic water withstrong sterilizing capability may be generated on the surface of theanode 64 by reducing the chlorine ions into gaseous chlorine anddissolving it in the slightly acidic (e.g., pH of approximately 4 to 6)water in the electrolytic chamber 55. Circulating the hypochlorousacidic water generated in this manner to all parts of the water flowpath in the apparatus completes disinfection and rinsing thereof.

Next, in the membrane regenerating process, the following testing iscarried out for the purpose of examining how an appropriate criticalcurrent density changes when the hardness of the to-be-electrolyzed rawwater is varied.

The following three types of test water differing in hardness areprepared by using ‘evian’ (registered trademark of S.A. des EauxMinerales d'Evian), which is supplied in Japan through Calpis ItochuMineral Water Co., Ltd., as reference water and appropriately dilutingit with ion-exchanged water. Note that hardness adjustment of the testwater can be easily carried out by measuring electric conductivity. Inaddition, the following total hardness and Ca hardness are actualmeasured values using a measuring kit.

(1) Test water 1: electric conductivity: 15 mS/m; total hardness: 80ppm; Ca hardness: 55 ppm(2) Test water 2: electric conductivity: 36 mS/m; total hardness: 195ppm; Ca hardness: 130 ppm(3) Test water 3: electric conductivity: 53 mS/m; total hardness: 295ppm; Ca hardness: 200 ppm

As preparation for testing, one set of the regenerating process iscarried out using ion-exchanged water to initialize (erase pastelectrolyzed functional water generation events and return theelectrolytic cell to an initial state) the electrolytic cell 17. Inother words, to begin with, reverse electrolysis is performed for twentyseconds with the pump 15 in an off state (without circulation),electrolysis is turned off and circulating is carried out for tenseconds, and then positive polarity electrolysis is performed for fourminutes and thirty seconds while circulating with the pump 15 in an onstate. After such regenerating process, the periphery of the waterstorage tank 13 is rinsed once with 800 cc of ion-exchanged water, andbefore beginning the testing, the periphery of the water storage tank 13is rinsed once with 300 cc of a test water.

The testing procedure is pouring 800 cc of respective test waters in thewater storage tank 13, and after carrying out circulating for one minutewith electrolysis turned off, circulating is carried out for sevenminutes through positive polarity electrolysis with six varied currentdensities (current density: 0/0.5/1/1.5/2/2.5 A/dm²). Having the timewhen circulating is concluded as a starting point while electrolysis isoff, the pH of the electrolytic functional water being circulated ismeasured and recorded for every minute thereafter. Note that toinitialize the electrolytic cell 17 at each time testing of one testwater is concluded, a one set of the regenerating process, rinsing usingion-exchanged water, and rinsing using the next test water is carriedout.

Results of carrying out testing in the manner are given in FIGS. 26through 29. FIGS. 26 through 29 show graphs regarding characteristicchanges over time of pH changing rates when the test water hardness isvaried in three ways for describing that critical current densitychanges according to change in test water hardness.

It can be understood from the testing results of FIGS. 26 through 29that critical current density tends to be a low value in the case wherethe to-be-electrolyzed raw water in which the cation-exchange membraneis immersed is soft water, while it tends to be a high value in the casewhere the membrane-immersing water is hard water. If 2 A/dm², forexample, is employed as a critical current density or the lower limit inorder to desorb cations adsorbed into the cation-exchange membranes 59and 60 using the electrolytic cell 17 according to this embodiment,membrane regeneration is possible even with the test water 3 (totalhardness: 295 ppm, Ca hardness: 200 ppm). More specifically, itdemonstrates that employment of, for example, 2 A/dm² as the criticalcurrent density is sufficient as long as it is to-be-electrolyzed rawwater with a total hardness of up to approximately 300 ppm.

1. A performance maintaining method for an electrolyzed functional watergenerating apparatus, which comprises an electrolytic chamber to whichto-be-electrolyzed raw water is supplied, at least one separatingmembrane which separates the inside of the electrolytic chamber from theoutside thereof, at least a pair of electrode plates provided inside andoutside the electrolytic chamber sandwiching the separating membrane, anelectrolytic cell in which the electrode plate outside the electrolyticchamber is provided in contact with the separating membrane, and a DCpower source that supplies a DC voltage between electrodes in theelectrolytic cell; said method employing a cation-exchange membrane asthe separating membrane and comprising: regenerating a membrane byapplying a DC voltage from the DC power source between a cathode or anelectrode plate provided inside the electrolytic chamber and an anode oran electrode plate outside the electrolytic chamber in a forwarddirection in a state where the electrolytic chamber is supplied withto-be-electrolyzed raw water; wherein cations such as calcium ions ormagnesium ions adsorbed into the cation-exchange membrane are desorbedwhile the to-be-electrolyzed raw water is subjected to electrolysis witha positive polarity so as to regenerate the membrane.
 2. The performancemaintaining method for an electrolyzed functional water generatingapparatus set forth in claim 1, wherein a DC voltage from the directcurrent source is applied in a forward direction between bothelectrodes, and a current density of the anode is set to a valueexceeding a critical current density or the lower limit in order todesorb cations adsorbed into the cation-exchange membrane.
 3. Theperformance maintaining method for an electrolyzed functional watergenerating apparatus set forth in claim 1, wherein a regeneration levelof the cation-exchange membrane is grasped based on changes in PH overtime of electrolyzed functional water resulting from subjecting theto-be-electrolyzed raw water to the electrolysis with a positivepolarity.
 4. The performance maintaining method for an electrolyzedfunctional water generating apparatus set forth in claim 1, furthercomprising a reverse descaling process of applying a DC voltage with areverse polarity from the DC power source between the cathode or theelectrode plate provided inside the electrolytic chamber and the anodeor the electrode plate outside the electrolytic chamber in a state whereto-be-electrolyzed raw water is supplied to the electrolytic chamber. 5.The performance maintaining method for an electrolyzed functional watergenerating apparatus set forth in claim 4, wherein once the reversedescaling process is carried out, the membrane regenerating process iscarried out.
 6. The performance maintaining method for an electrolyzedfunctional water generating apparatus set forth in claim 1, wherein themembrane regenerating process is intermittently carried out.
 7. Theperformance maintaining method for an electrolyzed functional watergenerating apparatus set forth in claim 1, wherein soft water is used asthe to-be-electrolyzed raw water supplied to the electrolytic chamberwhen regenerating the cation-exchange membrane while subjecting theto-be-electrolyzed raw water to the electrolysis with a positivepolarity.
 8. The performance maintaining method for an electrolyzedfunctional water generating apparatus set forth in claim 1, whereindeionized water is used as the to-be-electrolyzed raw water supplied tothe electrolytic chamber when regenerating the cation-exchange membranewhile subjecting the to-be-electrolyzed raw water to the electrolysiswith a positive polarity.
 9. The performance maintaining method for anelectrolyzed functional water generating apparatus set forth in claim 1,wherein replacing the to-be-electrolyzed raw water supplied to theelectrolytic chamber is carried out when regenerating thecation-exchange membrane while subjecting the to-be-electrolyzed rawwater to the electrolysis with a positive polarity.
 10. The performancemaintaining method for an electrolyzed functional water generatingapparatus set forth in claim 9, wherein replacing the to-be-electrolyzedraw water supplied to the electrolytic chamber is carried out bycirculating the to-be-electrolyzed raw water.